Rüdiger-Riehl-Award
By awarding the Rüdiger Riehl Prize to Dr Alexander Cerwenka, the GfI has recognised the outstanding achievements of young scientists in the field of ichthyological research.
Rüdiger Riehl, founding member of GfI
Rüdiger Riehl was one of the founding members of the Society for Ichthyology. He was an enthusiastic ‘fish lover’ with a wide range of interests. His research focused primarily on oogenesis (egg formation) and the formation of the micropyle (the opening in the egg shell through which sperm enters the egg) in fish eggs, as well as their structural variability within true bony fish. Other work included observations on the diversity and function of adhesive filaments, as well as on the fine structure of bone cells in the gonopodium of the dwarf carp.
He remains unforgettable to a very wide readership thanks to his Aquarium Atlas, which remains an indispensable reference work.
Rüdiger Riehl helped shape the fortunes of the GfI for many years as its treasurer and was also involved in other areas, such as the DCG and the organisation of the Düsseldorf symposia on the biology of aquarium fish, promoting the link between aquatics and research.
Award winner
The 2015 Rüdiger Riehl Prize was awarded to Dr Alexander Cerwenka in recognition of the scientific achievements in his doctoral thesis entitled:
”Phenotypic and genetic differentiation of invasive gobies in the upper Danube River“.
The invasive goby species that Mr Cerwenka has been working on in the upper Danube – Ponticola kessleri and Neogobius melanostomus – are representative of a large number of invasive fish species that are conquering and changing our native water systems as newcomers. Their impact on native species and ecosystems is only beginning to be understood. Under the supervision of Dr Uli Schliewen (ZSM) and Prof. Dr Jürgen Geist (Technical University of Munich), Alexander Cerwenka used morphometric and genetic approaches to investigate differentiation processes in invasive populations of the two goby species and to explore the influences of geographical, ecological and species-specific factors. This included investigating the origin of the species – a challenge that only sounds trivial at first glance – considering phenotypic plasticity, and differentiating between invasive populations.
Particularly exciting is the first-ever detection of hybridisation between two invasive species, as well as the observation of the very rapid formation of population structure in these invasive fish. The work thus makes notable contributions to invasion biology that go beyond the analysis of local fish population spread. This can also be seen in the publications that have since appeared, including in Aquatic Invasions and Hydrobiologia.
Dissertation Dr. Alexander Cerwenka: Phenotypic and genetic differentiation of invasive gobies in the upper Danube River